TAXPAYERS face a £15million bill for an empty prison that may never re-open.
The jail will stay shut for at least another year following a gas leak.
But a report warns the Ministry of Justice will have to pay the huge sum on the lease at Dartmoor Prison even if it remains closed.
Staff at the 200-year-old Napoleonic-era jail in Devon discovered high radon gas levels in December 2023.
Most inmates at the 700-capacity Category C prison were moved out soon after, with the final 175 relocated in July and August.
Last December, officials at the Prison Service renewed a 25-year lease, worth £37.5million, with Prince William’s Duchy of Cornwall.
That must be paid for at least the next ten years — potentially wasting up to £15million of taxpayers’ cash at £1.5million a year.
Meanwhile, ministers have pledged to build four new jails in the next seven years amid a severe cells shortage.
In September, The Sun on Sunday revealed high levels of radon were first detected at Dartmoor a year ago.
The radioactive gas, which can cause lung cancer, is created by the decay of uranium in rocks and soil.
Levels were ten times above the maximum allowed.
The prisons Independent Monitoring Board said: “The board was told the closure of the prison could be temporary but, if so, the earliest it could reopen would be 2026.
“If the closure were to be permanent, the lease requirements would have to be met at, potentially, some considerable cost.”
Last week, Prisons Minister Lord Timpson refused to rule out shutting the jail.
Conservative MP Sir Alec Shelbrooke insisted: “This is a mega-farce. There is no value for taxpayers’ money here, whatever happens.”
An MoJ spokeswoman said: “We continue to take advice from specialists to explore how it can be reopened as quickly as possible.”
